1. Field of the Invention
The subject of this invention is a method of obtaining high-quality products from polyolefin waste material or polyolefins, including kerosene, and in particular cosmetic kerosene, white oils, cosmetic paraffin, and other high-quality types of paraffins and aliphatic hydrocarbons. The products do not contain sulfur, nitrogen, other types of organic compounds, and double bonds. The products may be used, e.g., as components of fuels.
2. Description of the Related Art
Polyolefins are used to manufacture packages, utensils, containers, as well as construction materials.
Conventional methods of processing polyolefin waste material include thermal and catalytic destruction, which is carried out in the temperature range of between 350 and 450° C., depending on the catalyst used, to obtain a mixture of hydrocarbons, mainly aliphatic hydrocarbons of straight or branched-chain type, to be used as components of liquid fuels.
The process of thermal and catalytic destruction can be run in such a way that the liquid product obtained covers a wide range of hydrocarbons characterized by a boiling point from around 70° C. up to 600° C. These hydrocarbons are partly unsaturated and contain a considerable number of double bonds that, due to their chemical reactivity, reduce the stability of the product and cause allergy, reducing their value as components of fuels and making it impossible for them to be used to manufacture products of higher quality, including cosmetic kerosene, white oils, and paraffin.
Cosmetic kerosene is a fraction composed mainly of aliphatic hydrocarbons with the boiling temperature limit of about 180-275° C. that must meet high requirements with respect to purity, must not contain any aromatic hydrocarbons, and can contain only small amounts of sulfur compounds, nitrogen compounds, and other impurities.
White oils are oils that are composed mainly of aliphatic hydrocarbons having a high degree of purity, and having a boiling point between 260 and 400° C., that do not contain any aromatic hydrocarbons and contain only very small amounts of sulfur compounds, nitrogen compounds, and other impurities. White oils, as technical oils of a high degree of purity, are widely used in many industrial sectors as auxiliaries in technological processes, components of chemical formulations, as well as lubricants having a high degree of purity. Medical white oils of the highest purity degree are employed in food, pharmaceutical, and cosmetic industries.
Paraffin is a mixture of high-molecular weight aliphatic hydrocarbons having a boiling temperature of approximately 360-600° C.
Several types of paraffins are manufactured from refined raw products, starting from paraffin wax to cosmetic paraffin that differ from one another in having different contents of oil and impurities, such as sulfur and nitrogen compounds in particular.
Conventionally, to manufacture kerosene, including cosmetic kerosene, white oils, and paraffin, raw materials of refinery origin have been used. The raw materials must be refined in order to remove almost completely any sulfur compounds and nitrogen, as well as aromatic and unsaturated hydrocarbons. This process comprises several hydrogenation steps catalyzed by selective catalysts, mainly based on noble metals, that enable far-reaching, although not complete, removal of sulfur and nitrogen compounds.
Obtaining pure aliphatic hydrocarbons, not containing sulfur and aromatic hydrocarbons, from raw materials is a very difficult task, if at all possible on a large scale.